JP2002210329A - Detoxification system for ammonia gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an innovative detoxification system in which the treatment space and the entire apparatus are simplified and miniaturized by making it possible to send water for detoxifying ammonia gas leaking out a freezer unit of a freezing and air conditioning facility to the treatment space without requiring a pump. SOLUTION: The detoxification system 1 for ammonia gas is for detoxifying ammonia gas leaking out of a freezing unit 2 by introducing the ammonia gas into a closed treatment space 3 and producing a salt by carbonic acid gas and water and a transportation pipe 24 of the carbonic acid gas supplied to the closed treatment space 3 is joined to a water supply pipe 27 by an ejector 6 before the ammonia gas reaches the treatment space and at the time of supplying water to the closed treatment space 3, negative pressure is generated in the water supply pipe 27 facing to the joining part 25 by passing high pressure carbonic acid gas to the joining part 25 formed into a Venturi shape for carbonic acid gas and water to suck water out the water supply pipe 27 and send water together with carbonic acid gas to the closed treatment space 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detoxifying ammonia gas, and more particularly to a method of leaking from a refrigerator unit using ammonia as a refrigerant due to a sudden disaster or accident. Alternatively, the present invention relates to a detoxification system that effectively absorbs ammonia refrigerant that leaks due to long-term use and renders it harmless.

[0002]

BACKGROUND OF THE INVENTION In recent years, refrigerants applied to various types of refrigeration and air conditioning equipment have been shifted from specified CFCs to designated / substituted CFCs for the purpose of destruction of the ozone layer surrounding the earth and preventing global warming. At present, discharge of CFCs into the atmosphere is strongly regulated, and natural refrigerants such as ammonia have been reviewed. Naturally, ammonia has excellent properties as a refrigerant, so it has been used as a refrigerant in the past, but ammonia gas itself has a strong pungent odor, and it can be harmful if a large amount of human inhales it. Therefore, in recent years, it has not been used much as a refrigerant, but has been gradually reviewed for the above reasons.

[0003] In this type of refrigeration / air-conditioning equipment, if a refrigerant pipe is cracked due to, for example, a sudden disaster or accident, ammonia may leak, so that the leaked ammonia gas is harmless. An abatement device that can be released into the atmosphere after chemical conversion treatment is provided, and is legally required as an abatement regulation. In view of such circumstances, the present applicant has developed a method for efficiently removing the leaked ammonia gas, and has filed a patent application 200
0-174103 "Ammonia gas removal system" has been filed.

In Japanese Patent Application No. 2000-174103, the leaked ammonia gas is introduced into a closed space such as a scrubber or a cooling tower, where the leaked ammonia gas is neutralized with carbon dioxide gas and water to form a salt and thereby perform detoxification treatment. . When supplying water to a closed space such as a scrubber or a cooling tower, a pump is used to circulate the water stored in the tank until the water is almost equilibrated.

As described above, the detoxification method using a scrubber, a cooling tower or the like uses the water required for salt generation in a circulating manner, so that a suitable effect can be obtained in terms of effective use of water, but it is still described below. There was room for such development.
That is, in the above-mentioned Japanese Patent Application No. 2000-174103, a scrubber or a cooling tower is used as a closed space for removing ammonia gas, and for this reason, the closed space and, consequently, the entire apparatus must be enlarged. . In general, it is also necessary to attach a pump for supplying water to such a treatment space. For this reason, for example, in a small store or a tenant, the above-described abatement apparatus cannot always be installed in terms of space. There was something.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such a background, and is capable of sending water for detoxifying ammonia gas into a processing space without a pump. In this way, an attempt was made to develop a new abatement system that achieves simplification and downsizing of the processing space and, consequently, the entire apparatus.

[0007]

According to the first aspect of the present invention, there is provided an ammonia gas abatement system in which ammonia is applied as a refrigerant of a refrigeration / air-conditioning facility, and the ammonia gas leaked from a refrigerator unit of the facility is supplied to the atmosphere. Before discharging into the closed processing space, the salt is generated by the carbon dioxide gas and water in this space, and the ammonia gas is detoxified. It is connected so as to merge with a water supply pipe for generating salt at a stage before reaching the space, and when supplying water to the closed treatment space, high-pressure carbon dioxide gas is supplied to a junction of carbon dioxide gas and water. By flowing the water, a negative pressure is generated in the water supply pipe facing the junction, the water is sucked from the supply pipe into the junction, and the water is sent to the closed treatment space together with the carbon dioxide gas. Those made as characterized by the. According to the present invention, since a high-speed carbon dioxide gas is caused to flow at a junction with water, a negative pressure is generated in the water supply pipe, and water is supplied to the closed treatment space together with the carbon dioxide gas. It is not necessary to provide an active pump for supplying the air, and the closed processing space and the members attached to this space can be simplified. For this reason, the closed processing space can be formed in a simple cylindrical shape or a box shape, etc., which contributes to downsizing of the closed processing space and thus the abatement device. Installation is facilitated, and ammonia having excellent characteristics as a refrigerant is more easily used.

According to a second aspect of the present invention, in the ammonia gas removal system according to the first aspect, the transfer pipe for the carbon dioxide gas connected to the closed processing space has a pipe cross section at a junction with water. Are formed so as to increase the flow rate of the carbon dioxide gas. According to the present invention, since the speed of the carbon dioxide gas is further increased at the junction, the negative pressure of the water supply pipe facing the junction is increased, so that more water is sucked toward the junction and the water is reliably injected into the processing space. Ensure a proper water supply.

A third aspect of the present invention provides the ammonia gas removal system according to the first or second aspect.
After the water supplied to the closed processing space reacts with the ammonia gas, the water is recovered from the closed processing space, and the salt-containing solution is circulated and used until almost equilibrated. According to the present invention, the water for detoxifying the ammonia gas is used repeatedly until it is almost in an equilibrium state, so that a relatively small amount of water is required for the treatment,
Water can be used effectively.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ammonia gas elimination system 1 according to the present invention will be described below based on the illustrated embodiment.
The ammonia gas elimination system 1 of the present invention, which applies ammonia as a refrigerant, for example, effectively eliminates ammonia gas leaking from a compressor of a refrigerator or the like, as shown in FIG. 1 as an example. , A refrigerator unit 2, a closed processing space 3, a carbon dioxide gas cylinder 4,
It comprises a tank 5 and an ejector 6.
Hereinafter, each component will be described.

First, the refrigerator unit 2 will be described.
This device has the compressor 11 as a main member and appropriately includes a condenser, an evaporator, an expansion valve, and the like. The ammonia refrigerant is compressed by the compressor 11 to be in a high-temperature and high-pressure gas state, and then cooled by an air or water in a condenser to be in a liquid state. The pressure is appropriately reduced by the expansion valve, and the ammonia refrigerant is easily evaporated. After being brought into a gaseous state, it is sent to the evaporator, and after being subjected to a desired cooling, it is circulated and transferred to the compressor 11 again. In the present embodiment, since the purpose is mainly for refrigeration, the general term "refrigerator unit" is used, but the abatement system of the present invention is not necessarily limited to only refrigeration. And air conditioning such as cooling and heating.

The refrigerant applied to such a refrigerator unit 2 may leak in a relatively large amount due to a sudden disaster or accident, and particularly the ammonia refrigerant applied in the present invention may The substance itself has a strong pungent odor and is harmful if inhaled by a large amount (if the amount is relatively small, the ammonia absorbed in the body is discharged as urea). Therefore, the refrigerator unit 2
Is enclosed by a casing 12 in a sealed state.
In the case where the refrigerator unit 2 is stored in an appropriately partitioned room such as a machine room, for example, such a machine room or the like is formed so as to be hermetically sealed, and the casing 1
Applicable as 2. Further, the casing 12 is provided with a leak detector 13 for detecting leakage of ammonia gas inside, and an exhaust port 16 having an air supply port 14 on the air suction side and an exhaust fan 15 on the subsequent closed processing space 3 side. Each opening is formed so that the leaked ammonia gas can be smoothly guided to the processing space.

Next, the closed processing space 3 will be described. This space is a processing part for substantially detoxifying the ammonia gas introduced from the refrigerator unit 2, a receiving part 18 for introducing the ammonia gas, and a discharging part for discharging the processed gas to the atmosphere. 19 and is formed in a substantially cylindrical shape. Here, the receiving part 18 is the exhaust port 1
6, and a damper 20 for adjusting the introduction flow rate of the ammonia gas can be appropriately provided in the receiving portion 18. The discharge section 19 is provided with an eliminator 21 which plays a filter function and mainly removes moisture of the processed gas, and an exhaust fan 22.
As described above, the processing space is a part where the leaked ammonia gas is guided and processed while the receiving part 18 and the discharging part 19 are opened, so that the processing space is a substantially closed box-shaped space.

In the abatement method of the present invention, the leaked ammonia gas is neutralized with carbon dioxide gas and water.
Since an harmless salt that can be reused as fertilizer or the like is generated, an ejector 6 for supplying carbon dioxide and water to the closed processing space 3 is provided between the receiving unit 18 and the discharging unit 19. It is. The ejector 6 supplies high-pressure carbon dioxide gas at the junction of the carbon dioxide gas and the water, and supplies water to the closed processing space 3 together with the carbon dioxide gas by the entrainment of the carbon dioxide gas jet. It will be described later. For this reason, in this system, it is not necessary to add a pump for sending water into the closed processing space 3, and the configuration of the processing space and thus the abatement apparatus is simplified. In addition, due to such circumstances, the closed processing space 3 can be formed in a simple tubular or box-like shape, thereby achieving a reduction in size of the abatement apparatus.

Next, the carbon dioxide gas cylinder 4 will be described.
This is a supply source of carbon dioxide gas for removing ammonia gas, and supplies carbon dioxide gas to the closed processing space 3 via the transfer pipe 24 when the valve is opened. The transfer pipe 24 is connected so as to merge with a pipe for sending water required for the detoxification treatment before reaching the closed treatment space 3, and as an example, as shown in the enlarged view of FIG. The merging portion 25 is formed in a venturi shape or a nozzle shape so as to narrow the cross section of the pipe, and the merging portion 25 further increases the flow rate of the carbon dioxide gas in the high pressure state. Thus, the transfer pipe 2
Reference numeral 4 has a relatively large diameter portion, a small diameter portion, and a tapered portion as a transition portion between these portions. The large diameter portion 24a, the small diameter portion 24b, and the tapered portion 24c are denoted by reference numerals, respectively. Attach. The small-diameter portion 24b substantially forms the junction 25 between carbon dioxide and water.
Incidentally, the flow velocity of the carbon dioxide gas flowing through the large-diameter portion 24a before the merging is, for example, about 20 m / sec. This is a funnel-shaped small-diameter portion 24b (merging portion 25) as shown in FIG.
As an example, the jet is accelerated at a speed of about 300 m / sec or more. By this jet, the carbon dioxide gas is sent into the closed processing space 3 while entraining water.

Next, the tank 5 will be described. This is a part for storing water necessary for removing ammonia gas and a part for storing a solution containing salts and the like generated by the reaction, whereby the water is substantially equilibrated. Circulation is used between the tank 5 and the closed processing space 3. Here, a pipe for sending water required for the reaction from the tank 5 to the closed processing space 3 is provided by a supply pipe 27, and a solution containing salts and the like generated by the reaction is supplied from the closed processing space 3 to the tank 5.
The pipe to be sent to is referred to as a recovery pipe 28. As described in the description of the transfer pipe 24 (see the enlarged view of FIG. 1), the supply pipe 27 is formed so as to join the carbon dioxide gas at the small diameter portion 24b.

The water for producing the salt is first supplied from the water supply port into the tank 5, and then is sucked up through the supply pipe 27 by the suction action at the junction 25.
After that, the water is mixed with carbon dioxide in the ejector 6 and guided to the closed treatment space 3, and after a part of the water is used for salt generation,
The salt-containing solution is dropped into the tank 5 through the collection pipe 28 and collected. Thus, a solution containing water or salt,
The liquid that circulates between the tank 5 and the closed processing space 3, and the liquid that repeats this circulation (collectively referred to as the above-mentioned water and solution) becomes fresh water in a state where the above-mentioned neutralization reaction is almost in equilibrium. Is replaced as appropriate.

Next, the ejector 6 will be described. This is to supply the water required for neutralization to the closed processing space 3 while supplying the carbon dioxide gas required for neutralization to the processing space, and to perform a so-called pump action for transporting water, which is substantially as described above. It comprises a carbon dioxide transfer pipe 24 and a water supply pipe 27. That is, in this embodiment, the transfer pipe 2
4 is formed into a venturi shape or a nozzle shape, so that the flow rate of the carbon dioxide gas, which is originally in a high-pressure state, is further increased at the merging portion 25, and the water supply pipe facing the merging portion 25 is formed. 27 effectively produces a negative pressure. By this negative pressure, water is sucked from the supply pipe 27 to the junction 25, mixed with carbon dioxide, and atomized without supplying a pump, and the mixture of both is supplied to the closed processing space 3. In addition, since water is atomized and supplied, the water is more likely to react with ammonia gas or carbon dioxide gas than when it is simply liquid, and the detoxification treatment can be performed efficiently. If the flow rate of the mixture of carbon dioxide and water is to be positively adjusted, for example, the flow rate can be freely opened and closed between the time when the carbon dioxide gas joins the water and the time when the carbon dioxide gas reaches the closed processing space 3. It is possible to provide a valve.

The ammonia gas thus detoxified is brought into contact with carbon dioxide and water in the closed processing space 3 to cause a neutralization reaction, and is fixed as a salt such as ammonium carbonate or ammonium hydrogen carbonate. Hereinafter, representative examples of this reaction formula will be shown.

[0020]

## STR1 ## 2NH ₃ + CO ₂ + H ₂ O → (NH ₄ ) ₂ CO
₃ or

[0021]

## STR2 ## NH ₃ + CO ₂ + H ₂ O → NH ₄ .HCO ₃

As can be understood from the above equation, the amount of water required for salt formation depends on the amount of leaked ammonia gas. Therefore, the water supplied from the tank 5 generally hardly completely reacts in a single circulation, and until the neutralization reaction is substantially equilibrated even after being stored in the tank 5. Used repeatedly. Salts such as ammonium carbonate and ammonium hydrogen carbonate generated by the reaction are harmless and can be reused as fertilizers and the like.

[Other embodiments]

The present invention is based on the above-described embodiment as one basic technical idea. However, the following modifications are conceivable. First, the embodiment shown in FIG.
A transfer pipe 24 for carbon dioxide gas is provided at a junction 25 with water.
Although it was formed in a venturi shape or a nozzle shape so as to slightly narrow it, and the flow rate of the carbon dioxide gas was further increased, water was supplied from the supply pipe 27 only by the flow rate of the carbon dioxide gas sent from the carbon dioxide gas cylinder 4. In the case where the suction can be performed sufficiently, it is not always necessary to narrow down the flow path of the junction 25,
For example, it is possible to form a substantially flow path cross section of carbon dioxide gas in a substantially constant state over the entire length of the transfer pipe 24.

In the embodiment shown in FIG. 2, the detoxification process itself for producing salt substantially follows the basic embodiment described above, but the refrigerating unit 2 is provided in the water circulation path. Of the refrigerator unit 2 is cooled by water (solution) circulating between the tank 5 and the closed processing space 3. That is, the water required for the generation of salt is first supplied from the water supply port into the tank 5 and then transferred to the refrigerator unit 2 by the suction action at the junction 25 to cool the condenser.
After that, the water is sent from the supply pipe 27 to the closed processing space 3 by the ejector 6, and a part of the water is dropped into the tank 5 from the closed processing space 3 as a solution containing salt while being used for the generation of salt. Of course, the liquid circulated in such a manner (collectively referred to as the above-mentioned water and solution) can be appropriately replaced with fresh water in a state where the neutralization reaction for producing the salt is substantially in equilibrium. Note that this form is used when the solution containing salt is cooled while passing through the closed processing space 3 and has the ability to cool the condenser of the refrigerator unit 2.
This is a particularly effective form, and is a form in which water can be more effectively utilized.

[0025]

According to the ammonia gas removal system according to the first aspect, the water supplied to the closed processing space 3 is:
Since it is fed by the entrainment action of the carbon dioxide gas jet, there is no need to particularly provide a pump or the like.
Consequently, the abatement apparatus can be configured under a simple structure. Also, due to this, the closed processing space 3 can be formed in, for example, a simple cylindrical shape or a box shape, so that the processing space and the abatement apparatus can be reduced in size, and the site space is relatively small. Also makes it easier to install abatement equipment at stores, etc.
The usability of the ammonia refrigerant can be further improved.

Further, according to the ammonia gas elimination system of the second aspect, the transfer pipe 24 for supplying the carbon dioxide gas comprises:
At the junction 25 with water, the flow velocity of the carbon dioxide gas in the high pressure state is further increased due to the narrowing in a venturi shape or a nozzle shape, whereby the water supply pipe 27 facing the junction 25 has a higher flow rate. Since a negative pressure is applied, water can be efficiently supplied to the closed processing space 3. In addition, since water is supplied in the form of a mist to the processing space, it easily reacts with the ammonia gas, and the neutralization reaction is promoted.

Further, according to the ammonia gas removal system of the present invention, the water supplied to the closed treatment space 3 together with the carbon dioxide gas is partially used for the generation of salt by neutralization. Since the salt-containing solution is repeatedly used until it is almost in an equilibrium state, water is used more effectively, and the running cost is reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an ammonia gas removal system of the present invention.

FIG. 2 is an explanatory view showing another embodiment in which a condenser of a refrigerator unit is cooled by water (solution) circulating between a tank and a closed processing space.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ammonia gas removal system 2 Refrigerator unit 3 Closed processing space 4 Carbon dioxide gas cylinder 5 Tank 6 Ejector 11 Compressor 12 Casing 13 Leak detector 14 Air supply port 15 Exhaust fan 16 Exhaust port 18 Receiving part 19 Discharge part 20 Damper 21 Eliminator Reference Signs List 22 exhaust fan 24 transfer pipe (carbon dioxide) 24a large diameter part 24b small diameter part 24c taper part 25 junction part 27 supply pipe (water) 28 recovery pipe

Claims (3)

[Claims] 1. Ammonia is applied as a refrigerant of a refrigeration / air-conditioning facility, and ammonia gas leaked from a refrigerator unit of the facility is guided to a closed processing space before being discharged into the atmosphere. When the salt is generated and the ammonia gas is detoxified, the transfer pipe for the carbon dioxide gas supplied to the closed processing space joins with the water supply pipe for generating the salt before reaching the processing space. In supplying water to the closed processing space, by supplying high-pressure carbon dioxide gas to the junction of carbon dioxide and water, a negative pressure is generated in the water supply pipe facing the junction. Ammonia gas abatement system characterized in that water is sucked from a supply pipe into a junction, and water is fed into the closed treatment space together with carbon dioxide gas. 2. A transfer pipe for carbon dioxide gas connected to the closed processing space has a narrow pipe cross section at a junction with water.
2. The ammonia gas removal system according to claim 1, wherein the system is formed so as to further increase the flow rate of the carbon dioxide gas. 3. The water supplied to the closed processing space reacts with ammonia gas, is recovered from the closed processing space, and is circulated and used until the salt-containing solution is substantially equilibrated. The ammonia gas removal system according to claim 1 or 2,